...
- you need to select at least "unix" to use the farm. you can also select a windows account if you think you would use it (most short-term people would not).
- for email preferences select "none" if you are going to be short-term with the group (this will forward your email to the existing address you entered on the form). most longer term people choose "exchange" for their email, but some unix gurus prefer "unix" email.